Alfred cecil wright



NTTED STATES PATENT Enron.

DRAWING TUBES.

SPECIFICATION forming part of Letters Patent N 0. 609,718, dated August 23, 1898.

Application filed February 16, 1898. Serial No. 670,561. (No specimens.)

To all whom it may concern:

Be it known that I, ALFRED CEoIL WRIGHT, a subject of the Queen of Great Britain and Ireland, and a resident of 11 Pakenham road, Edgbaston, in the city of Birmingham, England, have invented certain new and useful Improvements Relating to the Drawing of Tubes, (for which I have filed an application for patent in Great Britain, No. 10,539, hearing date April 27, 1897,) of which the following is a specification.

This invention consists of improvements relating to the drawing of tubes through dies, and especially to the drawing of weldless steel tubes, my object being to expedite and cheapen the operation of reducing or elongating the rolled tube or tube-billet to the required finished dimensions for cycle construction and for other purposes.

In the drawing of tubes or tube-billets in accordance with my invention I dispense with the use of oil or grease such as is ordinarily employed; but I prevent the actual contact of the surfaces of the tube with the dies and mandrel by an interposing film of antifriction metal, and such metal by gliding through the die along with the tube acts as an efficient lubricant exactly in the place required and is not pushed oif the tube at the diemouth, as with the ordinary lubricants. The antifriction metal consists of a mixture of six parts tin to four parts lead and it is applied either by the immersion of the tube or tube-billet in a bath of the molten metal before commencing the drawing operation or by the immersion of the die and mandrel in the molten metal. After immersing the die and mandrel in the molten antifriction metal I draw through the die a dummy tube or mandrel and draw the mandrel through a dummy die for the purpose of forcing the soft coating of the said antifriction metal into the working surface of the die and mandrel, respectively. The soft metal is thus consolidated With the harder metal.

After being coated with the antifriction metal, or after the mandrel and dies have been coated and the coating consolidated in the manner described, the tube is placed on i the mandrel and is then drawn through a series of dies of slightly-varying dimensions to reduce it to the required finished size. The

tube is not removed from the mandrel after each pass through a die; neither is it annealed draw it through a series of six dies until reduced to the required finished size. After leaving each die the tube is reeled or released from the mandrel (but not removed from the same) before being passed through the next in the series.

By my invention I am enabled to dispense entirely with the use of oil, grease, or like unctuous substances to effecta great saving in the wear of dies and mandrels and to very materially reduce the expenditure of mechanical energy and the time required for the drawing or reducing operation. My process also permits of the employment of a cheaper steel for the production of weldless steel tubes for cycles and other constructional purposes, the tubes produced from such steel by my process being quite equal in quality to the tubes produced in the ordinary manner from Swedish steel. I am also enabled to draw tubes of hard white metal and other alloys such as cannot be drawn without my process and to facilitate the drawing of copper, brass, and the like tubes.

Having now described my invention, what I claim as new, and desire to secure by Letters Patent, is-

The herein-described process of drawing tubes with dies consisting in coating one of the contacting surfaces with antifriction metal; mounting the tube on a mandrel; drawing the tube and mandrel through the dies in succession without intermediate an nealing or pickling and releasing the tube from the mandrel after each pass through a die without removing the tube from the ma11- drel, substantially as described.

In witness whereof I have hereunto set my hand in presence of two witnesses.

ALFRED CECIL WRIGHT.

Witnesses:

EDWARD MARKS, HERBERT BowKErr. 

